Web damping nozzle system



H. H. HERING, JR

WEB DAIPING NOZZLE SYSTEM Feb. 24, 1910 3 Sheets-Sheet 1 v Filed larch 1s, 1968 k 5 QE QQ Q3 Feb. 24, 1970 H; H. mm, m 3.49

WEB murme NOZZLE syswma Filed March 18, 1968 3 Sheets-Sheet 2 FIG, 5

Feb. 24, 1970 H, HERING, JR 3,496,648

was Burma uozzLE sYs'rEu' Filed Ilaroh 18, 1968 3 Sheets-Sheet 5 United States Patent 3,496,648 WEB DAMPING NOZZLE SYSTEM Henry H. Hering, Jr., Homewood, Ill., assignor to B. Olren & Co., Inc., Chicago, 11]., a corporation of Illinois Filed Mar. 18, 1968, Ser. No. 713,620 Int. Cl. F26b 13/12 U.S. Cl. 34156 11 Claims ABSTRACT OF THE DISCLOSURE A construction for reducing vibrations in elongated webs which are moved between widely spaced-apart points while being suspended between these points. The vibration suppressing means comprise a pair of air nozzles for directing streams of air against the web from opposite sides of the web. The nozzles are positioned at spaced locations along the length of the web whereby the air streams impart an S-shaped configuration to the web. Furthermore, the air streams which are directed against the web are di vided into a downstream and an upstream portion with the upstream portion being passed to return ducts associated with the nozzles.

This invention is directed to constructions employed for the handling of webs, particularly constructions capable of handling webs moving at relatively high speeds.

There are many applications which require the handling of webs of material wherein the material is suspended between spaced-apart points while being out of contact with solid surfaces during movement between these points. For example, dryers employed for the drying of webs of material such as paper and cloth fabrics are designed so that any printing on the webs will not be damaged during the drying operation. In web offset printing constructions, a web of material must be moved from the last printing roll and then through a long dryer without any contact with supporting rolls.

In order to accomplish printing and drying on an efficient basis, it is necessary to move the webs at extremely high speeds. When such operations are attempted, vibrations can be set up in the webs, and these vibrations may be of sufiicient amplitude to move the web into contact with solid surfaces whereby the printing on the web would be damaged. The instant invention will be described with reference to the handling of webs in offset printing machines. It will be appreciated, however, that the concepts described are also applicable to other web handling systems wherein it is desirable to reduce or eliminate vibra tions in materials handled in the system.

It is the general object o fthe instant invention to provide an improved means for the handling of webs whereby the webs can be safely transported for substantial distances while being suspended between spaced-apart points and while being otherwise maintained out of contact with solid surfaces.

It is a more particular object of this invention to provide a construction which accomplishes the foregoing objects, and which specifically eliminates or reduces vibrations in webs whereby the webs can be maintained in a substantially constant path of travel while being suspended between two widely spaced-apart locations and while being moved at high speed.

These and other objects of this invention will appear hereinafter and for purposes of illustration, but not of limitation, specific embodiments of the invention are shown in the accompanying drawings in which:

FIGURE 1 is a schematic illustration of a web handling construction characterized by the features of this invention;

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FIGURE 2 is a schematic illustration of air circulating means employed for the construction;

FIGURE 3 is a fragmentary plan view illustrating an air discharge nozzle and return duct assembly of the type employed in a construction characterized by the features of the invention;

FIGURE 4 is a vertical sectional view of the assembly taken about the line 44 of FIGURE 5;

FIGURE 5 is a front elevation of the assembly;

FIGURE 6 is a fragmentary view of the assembly illustrating a portion of the bracket means used in setting up the assembly;

FIGURE 7 is a fragmentary view illustrating the manner of attachment of the bracket means to a press frame;

FIGURE 8 is a view of the bracket means taken about the line 88 of FIGURE 7; and

FIGURE 9 is a fragmentary sectional view taken about the line 99 of FIGURE 6.

The web handling construction of this invention is generally concerned with the movement of material between two spaced-apart points. The particular improvement of this invention concerns a vibration suppressing means which acts on the web as it moves between such points. The suppressing means is particularly advantageous where the points are a substantial distance apart, therefore, requiring suspension of the web for a long distance without contact with solid surfaces, and the suppressing means is also of most value where the web is moving at high speeds.

FIGURE 1 illustrates the application of the invention to a standard web offset printing construction. In such a construction, a web of paper or the like is passed between printing rolls with the last set 10 of such rolls being illustrated. These rolls are included in a printing unit 12, and there may be several such sets of rolls, depending upon the printing operation. As the web moves beyond the last set of rolls, the printing ink is still wet and the web must still be moved through a dryer 14. After the web has passed out of the dryer, it is moved into, contact with chill rolls 16.

In many web drying constructions, for example, as referred to in Hering Patent No. 3,319,354, the web is maintained completely out of contact With solid surfaces between the last set of printing rolls and the chill rolls. This is particularly necessary where the web is printed on both sides since any contact with solid surfaces would tend to mar the printing.

In order to maintain the web in position as it passes through a dryer, and in order to assist in drying, air nozzles are provided for directing streams of air onto the web surfaces. As illustrated in the aforementioned patent, such nozzles may direct streams of air toward the opposite surfaces of the web with the web being maintained in position between the nozzles.

Where the web is moved at high speeds, there is a tendency for the web to vibrate and, in such case, contact with the air nozzle surfaces, or with other surfaces, becomes possible. The air nozzles 18 shown in FIGURE 1 are de signed to reduce or overcome this tendency to vibrate whereby the web can be safely passed through a dryer even though the web may be moving at high speed, and even though there is a substantial distance between the last set of printing rolls and the chill rolls.

As best shown in FIGURES 3, 4 and 5, the nozzles 18 consist of a plenum chamber 20 having an inlet 22. Air passing through the inlet 22 is distributed throughout the plenum chamber and is forced toward a plate 24 which is mounted in position across outlet 26. This outlet 26 and the plate 24 extend completely across the nozzle. The nozzle extends beyond the side edges of the web 28 3 whereby air streams issuing from the nozzles will contact the web across its entire surface.

A tubular support 30 extends along the length of the nozzle for supporting the plate 24. Sleeves 32 are associated with the support at intervals along its length, and bolts 34 fit within these sleeves for securing the support to side walls 36 of the nozzle.

The plate 24 has a width slightly less than the width of the outlet 26 whereby elongated slits 38 are defined along both side edges of the plate. The slits 38 provide openings for the passage of air streams out of the nozzle.

Each of the nozzles includes a return duct having a top sheet portion 40. A flange 42 is defined by the sheet 40, and the sheet is secured to the nozzle by means of the bolts 34 which extend through openings defined by the flanges.

The sheet 40 tapers outwardly away from the path of travel of the Web from its point of connection with the outlet 26 of the nozzle. At the outer end of the sheet 40, there is provided an inturned portion 44 which defines an opening comprising outlet 46. A hose can be attached to this outlet for withdrawing air from the return duct.

The duct sheet 40 defines a plurality of openings 48 for the entry of air. As will be more fully explained, air streams passing through upstream slits 38 will move into contact with the web, and then the air streams are drawn into the openings 48 for passage through the return ducts.

FIGURES 6, 7 and 8 illustrate the manner in which the nozzles and return ducts are secured in position in a typical operation. The securing means include arms 50 and .52 which extend outwardly from a bar 54 secured to the press frame 56 by means of bolts 58. Spacers 62 are secured to the arms 50 and 52 by means of bolts 63. Arms 64 are hung on pivot pins 66 which extend out from the spacers 62. Spring mounted pins 67 extend into openings in spacers '62 to fix the angular relationship of the arms 64 with associated arm 50 and 52. When the pins 67 are withdrawn, the arms 64 can be swung to an inoperative position. At this point, additional openings are provided in the spacers 62 whereby the pins 67 can lock the arms 64 in the inoperative position.

In FIGURE 5, the nozzles are shown spaced apart for clarification purposes. A typical operational relationship of the nozzle arms 64 is shown in FIGURE 7. Each of the arms 64 carries a bracket member 68. The bracket member, as best shown in FIGURE 6, defines opposed extensions 70 which define bores for receiving the ends 74 of threaded rod 76. An extension 80 of one end 74 carries an adjusting knob 82.

The threaded rod 76 is received within a threaded bore defined by a cylinder 86 which is received in circular bores defined by opposed elements 88. The elements 88 are attached to the end wall of the plenum chamber 20 of the nozzle 18. It will be appreciated when considering the structure described that the nozzles can be vertically adjusted by rotation of the knobs 82. The adjusting means are provided at either end of each of the nozzles.

FIGURE 2 illustrates schematically a proposed arrangement for the handling of air streams in a system of the type described. A blower 90 forces air through pipe 92 to a supply connection 94, and the supply connection divides the air between hoses 96. The respective hoses are attached to the inlet 22 of the plenum chambers 20 for the nozzles 18. The return ducts are each connected to hoses 98 which pass air to exhaust connection 100, and a pipe 102 directs the air back to the blower 90 to provide for complete circulation.

As previously indicated, two separate air streams issue from the nozzles 18, and since the elongated slits 38 are of the same dimension, the respective air streams are substantially equal in volume and intensity. As best illustrated in FIGURE 1, the air streams tend to remain divided with one of the air streams following the direction of the web, and with the other air stream moving upstream against the movement of the web. This latter stream is drawn into the return duct due to the suction effect created by the blower.

In the operation of the construction described, it is preferable to first locate the face of the nozzle nearest the dryer in position adjacent the web line. The other nozzle is then put into position, and the damper 104 for exhaust connection is placed in the wide open position as are the blast gates 106 for the supply connection 94. With the blower turned on, the nozzle nearest the printing unit is lowered until a definite S-shaped deflection occurs in the web.

If web vibration still continues, the same nozzle should be lowered until maximum damping it attained. With the adjustability features described, and through the use of the dampers and blast gates, ideal operating conditions can be easily accomplished. It will be appreciated in this connection that the supporting means for the nozzles may permit horizontal adjustment of the nozzle positions (e.g. by providing elingated slots for the bolts 63) as well as angular adjustment (e.g. by providing rotational adjusting means through stud 107 and lock nut 108 in FIGURE 7) whereby the best operating conditions can be achieved. When the nozzles are not in use, the connection achieved by the pins 66 and 67 permits rotation of the nozzles out of position whereby the nozzles need not be removed but will also not interfere with the other operations of the system.

Although it is diflicult to specifically analyze the reasons for the reduction in vibrations achieved by the instant invention, it is believed that the S-shape acts as a barrier to the wave motion generated by impulses transmitted to the web. Furthermore, the S-shape takes up additional web length which is caused by plastic flow.

When the S-shaped system is used without the return ducts, problems arise, particularly with respect to the press operation. The return ducts eliminate these difiiculties by picking up substantially all air which is directed toward the printing unit so that there is no danger of drying the ink during the printing operation.

It will be understood that various changes and modifications may be made in the above described construction which provide the characteristics of this invention without departing from the spirit thereof particularly as defined in the following claims.

That which is claimed is:

1. In a web handling construction wherein a length of material forming the web is suspended between spacedapart points and is moved between these points, the improvement comprising means located between said points for suppressing vibrations in said web as the web moves between said points, said suppressing means comprising a first air nozzle located on one side of said web and a second air nozzle located on the other side of said web, one of said air nozzles being located upstream of the other nozzle with each of said nozzles including air outlet openings which direct streams of air toward said web whereby an S-shaped configuration is imparted to the web in the vicinity of said nozzles and including return ducts associated with each of said nozzles and located upstream of the respective nozzles, and including means for directing at least some of said air passing out of said outlet openings upstream in opposition to the direction of web movement and over the respective surfaces of the web before passage into said return ducts.

2. A construction in accordance with claim 1 including an offset printing press and an associated drying apparatus, said spaced apart points comprising the last printing rolls of said press and the outlet of the drying apparatus, said web being carried through said drying apparatus subsequent to printing with the web being out of contact with supporting rolls, and wherein said suppressing means is located immediately upstream of the drying apparatus.

3. A construction in accordance with claim 1 wherein said nozzles discharge separate streams of air with a 5 portion of said air passing upstream into said return ducts and the balance of the air passing downstream in contact with the web surfaces.

4. A construction in accordance with claim 3 wherein said nozzles define elongated discharge ends extending the width of said web, a plate located within the openings defined by each discharge end, said plate having a width slightly less than the width of said opening whereby elongated slits extending the width of said web are defined along the opposite side edges of said plate, said slits comprising said air outlet opening.

5. A construction in accordance with claim 1 wherein the return ducts each comprise a top sheet member attached to said nozzles and extending along the length of said nozzles, a chamber defined between said top sheet, and a hose connection to said chamber for withdrawing air from the chamber, said top sheet defining inlet openings and being attached to an associated nozzle along a line in substantially the same plane as the outlet openings of the nozzle, each of said top sheets tapering outwardly away from the web from this line of connection with the nozzles.

6. A construction in accordance with claim 1 including means for adjusting the relative vertical positions of said suppressing means.

7. A construction in accordance with claim 6 wherein said suppressing means are attached to a bracket, said adjusting means comprising manually operable means for moving said suppressing means relative to said bracket.

8. A construction in accordance with claim 1 including means for adjusting the relative horizontal positions of said suppressing means.

9. A construction in accordance with claim 1 including means for adjusting the angular relationship of the suppressing means relative to the web.

10. A construction in accordance with claim 1 including air circulating means for drawing air into said return ducts whereby at least a portion of the air issuing from said outlet is positively drawn in a direction opposite the direction of movement of the Web and into said return ducts.

11. A construction in accordance with claim 2 wherein said air circulating means comprises an air blower having its intake end communicating with said return ducts.

References Cited UNITED STATES PATENTS 602,799 4/1898 Burns 34--156 1,926,306 9/1933 Petterson 34156 XR 2,081,945 6/1937 Massey et al. 34-156 XR 3,181,250 5/1965 Vits 34156 XR 3,257,734 6/1966 Boadway et al. 34-156 XR 3,384,282 5/1968 Vits 34-156 XR KENNETH W. SPRAGUE, Primary Examiner 

